Products and methods for delivery of polynucleotides by adeno-associated virus for lysosomal storage disorders

ABSTRACT

The present invention relates to methods and materials useful for systemically delivering polynucleotides across the blood brain barrier using adeno-associated virus as a vector. For example, the present invention relates to methods and materials useful for systemically delivering α-N-acetylglucosamidinase polynucleotides to the central and peripheral nervous systems, as well as the somatic system. Use of these methods and materials is indicated, for example, for treatment of the lysosomal storage disorder mucopolysaccharidosis IIIB. As another example, the present invention relates to methods and materials useful for systemically delivering N-sulphoglucosamine sulfphohydrolase polynucleotides to the central and peripheral nervous systems, as well as the somatic system. Use of this second type of methods and materials is indicated, for example, for treatment of the lysosomal storage disorder mucopolysaccharidosis IIIA.

This application is a divisional of U.S. patent application Ser. No.13/491,326 filed Jun. 7, 2012, which claims the benefit of the filingdate of U.S. Provisional Patent Application No. 61/494,635 filed Jun. 8,2011, which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to methods and materials useful forsystemically delivering polynucleotides across the blood brain barrierusing adeno-associated virus as a vector. For example, the presentinvention relates to methods and materials useful for systemicallydelivering α-N-acetylglucosamidinase polynucleotides to the central andperipheral nervous systems, as well as the somatic system. Use of thesemethods and materials is indicated, for example, for treatment of thelysosomal storage disorder mucopolysaccharidosis IIIB. As anotherexample, the present invention relates to methods and materials usefulfor systemically delivering N-sulphoglucosamine sulfphohydrolasepolynucleotides to the central and peripheral nervous systems, as wellas the somatic system. Use of this second type of methods and materialsis indicated, for example, for treatment of the lysosomal storagedisorder mucopolysaccharidosis IIIA.

INCORPORATION BY REFERENCE OF THE SEQUENCE LISTING

This application contains, as a separate part of disclosure, a SequenceListing in computer-readable form (46031A_SeqListing.txt; 22,737 byteASCII text file, created Jun. 7, 2012) which is incorporated byreference herein in its entirety.

BACKGROUND

Mucopolysaccharidosis (MPS) IIIB is a devastating lysosomal storagedisease (LSD) caused by autosomal recessive defects in the gene coding alysosomal enzyme, α-N-Acetylglucosaminidase (NAGLU). The lack of NAGLUactivity disrupts the stepwise degradation of a class of biologicallyimportant glycosaminoglycan (GAG), leading to the accumulation ofheparan sulfate oligosaccharides in lysosomes in cells of most tissues.Cells throughout the CNS are particularly affected, resulting in complexsecondary neuropathology. MPS IIIB infants appear normal at birth, butdevelop progressive neurological manifestations that lead to prematuredeath. Somatic manifestations of MPS IIIB occur in all patients, andinvolve virtually all organs, although they are mild relative to otherforms of MPS, such as MPS I, II and VII.

MPS IIIA is a related LSD caused by autosomal recessive defects in thegene encoding a lysosomal enzyme, N-sulphoglucosamine sulphohydrolase(SGSH). The lack of SGSH activity also disrupts the stepwise degradationof a class of biologically important GAG, leading to the accumulation ofheparin sulfate oligosaccharides in lysosomes in cells of most tissues.

No treatment is currently available for MPS IIIB or IIIA. For all of theMPS disorders, therapies have historically been limited to supportivecare and management of complications. MPS IIIB is not amenable to eitherhematopoietic stem cell transplantation or recombinant enzymereplacement therapy. These have instead been used to treat mostlysomatic disorders in patients with MPS I, II and IV. This is because theneuropathology of MPS IIIB is global and the blood brain barrier (BBB)precludes effective central nervous system (CNS) access.

For the majority of CNS diseases, effective treatments are rare sincethe CNS is located in a well protected environment and isolated by ahighly defined anatomical/functional barrier. The BBB is completelyformed at birth in humans. In general, the BBB protects the CNS byselectively regulating the transport of molecules/agents from the bloodcirculation into the CNS or vice versa Likewise, it prevents potentialtherapeutics from entering the CNS. The BBB remains the most criticalchallenge to developing therapies for CNS diseases, especially globalCNS disorders.

It is contemplated herein that gene therapy has potential for treatingLSDs because the secretion of lysosomal enzymes, including NAGLU andSGSH, leads to bystander effects thus reducing the demand for genetransfer efficiency. The adeno-associated virus (AAV) vector system isone system with demonstrated therapeutic effect in a great variety ofdisease models. To date, no known pathogenesis has been linked to AAV inhumans. Recombinant AAV (rAAV) vectors based on AAV serotype 2 (AAV2)have been used in numerous studies for neurological diseases,transducing both neuronal and non-neuronal cells in the CNS withdemonstrated therapeutic benefits in treating MPS and other LSDs inanimals and in patients with Parkinson's and Batten's disease. In themajority of rAAV-CNS gene therapy studies in LSDs, vectors weredelivered by direct intracranial injection, which has limited potentialfor treating global CNS diseases. See, Sands et al., Acta Paediatr.Suppl., 97: 22-27 (2008); Fu et al., Mol, Ther., 5: 42-49 (2002);Cressant et al., J. Neurosci., 24: 10229-10239 (2004); Fraldi et al.,Hum. Mol. Genet., 16: 2693-2702 (2007); Worgall et al., Hum. Gen. Ther.,19: 563-574 (2008) and Heldermon et al. Mol. Ther., 18: 873-880 (2010).To overcome these obstacles, more efficient delivery approaches havebeen developed with broad or global transduction, and functionalbenefits for the neurological disease in adult MPS IIIB mice. Anintracisternal injection of rAAV2-hNAGLU vector in adult MPS IIIB mice,following mannitol pretreatment, led to deep periventriculartransduction and clinical benefits. See Fu et al., J. Gene Med., 12:624-633 (2010). Intravenous (IV) rAAV injection into neonatal MPS I, MPSVII and MPS IIIB mice led to long-term correction of lysosomal storagein both somatic and CNS tissues. See, Sands et al., Lab. Anim. Sci., 49:328-330 (1999); Hartung et al., Mol. Ther., 9: 866-875 (2004) andHeldermon et al., supra. However, the BBB may still be permeable inneonatal mice while closed at birth in humans. Previously, in adult MPSIIIB mice, pretreatment with an N infusion of mannitol transientlydisrupting the BBB facilitated the CNS entry of IV-delivered rAAV2,resulting in diffuse global CNS transduction and neurologicalcorrection. See, McCarty et al., Gene Ther., 16: 1340-1352 (2009).

Recombinant AAV9 vectors encoding the sulfamidase enzyme have beenadministered to MPSIIIA mice as reported in Ruzo et al., XVIII AnnualCongress of the European Society of Gene and Cell Therapy: 1389(Abstract Or 96) (October 2010) and Ruzo et al., Mol. Therap., 20(2):254-266 (2012).

Adeno-associated virus (AAV) is a replication-deficient parvovirus, thesingle-stranded DNA genome of which is about 4.7 kb in length including145 nucleotide inverted terminal repeat (ITRs). The nucleotide sequenceof the AAV serotype 2 (AAV2) genome is presented in Srivastava et al., JVirol, 45: 555-564 (1983) as corrected by Ruffing et al., J Gen Virol,75: 3385-3392 (1994). Cis-acting sequences directing viral DNAreplication, encapsidation/packaging and host cell chromosomeintegration are contained within the ITRs. Three AAV promoters (namedp5, p19, and p40 for their relative map locations) drive the expressionof the two AAV internal open reading frames encoding rep and cap genes.The two rep promoters (p5 and p19), coupled with the differentialsplicing of the single AAV intron (at nucleotides 2107 and 2227), resultin the production of four rep proteins (rep 78, rep 68, rep 52, and rep40) from the rep gene. Rep proteins possess multiple enzymaticproperties that are ultimately responsible for replicating the viralgenome. The cap gene is expressed from the p40 promoter and it encodesthe three capsid proteins VP1, VP2, and VP3. Alternative splicing andnon-consensus translational start sites are responsible for theproduction of the three related capsid proteins. A single consensuspolyadenylation site is located at map position 95 of the AAV genome.The life cycle and genetics of AAV are reviewed in Muzyczka, CurrentTopics in Microbiology and Immunology, 158: 97-129 (1992).

AAV possesses unique features that make it attractive as a vector fordelivering foreign DNA to cells, for example, in gene therapy. AAVinfection of cells in culture is noncytopathic, and natural infection ofhumans and other animals is silent and asymptomatic. Moreover, AAVinfects many mammalian cells allowing the possibility of targeting manydifferent tissues in vivo. Moreover, AAV transduces slowly dividing andnon-dividing cells, and can persist essentially for the lifetime ofthose cells as a transcriptionally active nuclear episome(extrachromosomal element). Furthermore, because the signals directingAAV replication, genome encapsidation and integration are containedwithin the ITRs of the AAV genome, some or all of the internalapproximately 4.3 kb of the genome (encoding replication and structuralcapsid proteins, rep-cap) may be replaced with foreign DNA such as agene cassette containing a promoter, a DNA of interest and apolyadenylation signal. The rep and cap proteins may be provided intrans. Another significant feature of AAV is that it is an extremelystable and hearty virus. It easily withstands the conditions used toinactivate adenovirus, making cold preservation of AAV less critical.AAV may even be lyophilized. Finally, AAV-infected cells are notresistant to superinfection.

Multiple serotypes of AAV exist and offer varied tissue tropism. Knownserotypes include, for example, AAV1, AAV2, AAV3, AAV4, AAV5, AAV6,AAV7, AAV8, AAV9, AAV10 and AAV11. AAV9 is described in U.S. Pat. No.7,198,951 and in Gao et al., J. Virol., 78: 6381-6388 (2004). Advancesin the delivery of AAV6 and AAV8 have made possible the transduction bythese serotypes of skeletal and cardiac muscle following simple systemicintravenous or intraperitoneal injections. See, Pacak et al., Circ.Res., 99(4): 3-9 (1006) and Wang et al., Nature Biotech., 23(3): 321-328(2005). The use of some serotypes of AAV to target cell types within thecentral nervous system, though, has required surgical intraparenchymalinjection. See, Kaplitt et al., Lancet 369: 2097-2105 (2007); Marks etal., Lancet Neurol 7: 400-408 (2008); and Worgall et al., Hum Gene Ther(2008).

There remains a need in the art for products and methods for treatinglysosomal storage disorders such as MPS IIIB and MPS IIIA.

SUMMARY

The present invention provides methods and materials useful forsystemically delivering polynucleotides such as NAGLU polynucleotides orSGSH polynucleotides across the BBB.

According to the invention, gene delivery is achieved by utilizing, forexample, AAV serotype 9 (AAV9). See, Foust et al., Nature Biotechnology,27: 59-65 (2009); Duque et al., Mol. Ther. 17: 1187-1196 (2009); andZincarelli et al., Mol. Ther., 16: 1073-1080 (2008). Vectors based onthis serotype or functionally-related serotypes are able to cross theBBB unaided in neonate and adult animals. An added benefit to using AAV9vectors is that pre-existing immunity is less common than for AAV2serotype. The use of rh74 serotype AAV vectors among others is alsocontemplated by the invention.

In one aspect, the invention provides a method of delivering a NAGLUpolynucleotide across the BBB comprising systemically administering arAAV9 with a genome including the polynucleotide to a patient. In someembodiments the rAAV9 genome is a single-stranded genome.

More specifically, the present invention provides methods and materialsuseful for systemically delivering NAGLU polynucleotides across theblood brain barrier to the central and peripheral nervous system. Insome embodiments, a method is provided of delivering a polynucleotide tothe central nervous system comprising systemically administering a rAAV9with a single-stranded genome including the genome to a patient. In someembodiments, a method of delivering a NAGLU polynucleotide to theperipheral nervous system comprising systemically administering a rAAV9with a single-stranded genome including the polynucleotide to a patientis provided.

Even more specifically, in some embodiments, the NAGLU polynucleotide isdelivered to brain. In some embodiments, the polynucleotide is deliveredto the spinal cord. In some embodiments, the NAGLU polynucleotide isdelivered to a lower motor neuron. In some embodiments, thepolynucleotide is delivered to nerve and glial cells. In someembodiments, the glial cell is a microglial cell, an oligodendrocyte oran astrocyte. In some, embodiments, the rAAV9 is used to deliver a NAGLUpolynucleotide to a Schwann cell.

Use of the NAGLU methods and materials is indicated, for example, fortreating Sanfilippo syndrome Type B/MPS IIIB.

In another aspect, the invention provides a method of delivering an SGSHpolynucleotide across the BBB comprising systemically administering arAAV9 with a genome including the polynucleotide to a patient. In someembodiments, the rAAV9 genome is a self-complementary genome. In someembodiments the rAAV9 genome is a single-stranded genome.

More specifically, the present invention provides methods and materialsuseful for systemically delivering SGSH polynucleotides across the bloodbrain barrier to the central and peripheral nervous system. In someembodiments, a method is provided of delivering a polynucleotide to thecentral nervous system comprising systemically administering a rAAV9with a self-complementary genome including the genome to a patient. Insome embodiments, a method of delivering a SGSH polynucleotide to theperipheral nervous system comprising systemically administering a rAAV9with a self-complementary genome including the polynucleotide to apatient is provided.

Even more specifically, in some embodiments, the SGSH polynucleotide isdelivered to brain. In some embodiments, the polynucleotide is deliveredto the spinal cord. In some embodiments, the SGSH polynucleotide isdelivered to a lower motor neuron. In some embodiments, thepolynucleotides is delivered to nerve and glial cells. In someembodiments, the glial cell is a microglial cell, an oligodendrocyte oran astrocyte. In some, embodiments, the rAAV9 is used to deliver a SGSHpolynucleotide to a Schwann cell.

Use of the SGSH methods and materials is indicated, for example, fortreating MPS IIIA.

In yet another aspect, administration of the rAAV9 encoding a NAGLU orSGSH polypeptide is preceded by administration of mannitol.

In still another aspect, the invention provides rAAV genomes comprisingone or more AAV ITRs flanking a polynucleotide encoding a NAGLU. TheNAGLU polynucleotide is operatively linked to transcriptional controlDNAs, specifically promoter DNA and polyadenylation signal sequence DNAthat are functional in target cells to form a gene cassette. The genecassette may also include intron sequences to facilitate processing ofan RNA transcript when expressed in mammalian cells.

In a further aspect, the invention provides rAAV genomes comprising oneor more AAV ITRs flanking a polynucleotide encoding an SGSH. The SGSHpolynucleotide is operatively linked to transcriptional control DNAs,specifically promoter DNA and polyadenylation signal sequence DNA thatare functional in target cells to form a gene cassette. The genecassette may also include intron sequences to facilitate processing ofan RNA transcript when expressed in mammalian cells.

The rAAV genomes of the invention lack AAV rep and cap DNA. AAV DNA inthe rAAV genomes (e.g., ITRs) may be from any AAV serotype for which arecombinant virus can be derived including, but not limited to, AAVserotypes AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-6, AAV-7, AAV-8, AAV-9,AAV-10 and AAV-11. The nucleotide sequences of the genomes of the AAVserotypes are known in the art. For example, the complete genome ofAAV-1 is provided in GenBank Accession No. NC_(—)002077; the completegenome of AAV-2 is provided in GenBank Accession No. NC_(—)001401 andSrivastava et al., J. Virol., 45: 555-564 {1983); the complete genome ofAAV-3 is provided in GenBank Accession No. NC_(—)1829; the completegenome of AAV-4 is provided in GenBank Accession No. NC_(—)001829; theAAV-5 genome is provided in GenBank Accession No. AF085716; the completegenome of AAV-6 is provided in GenBank Accession No. NC_(—)00 1862; atleast portions of AAV-7 and AAV-8 genomes are provided in GenBankAccession Nos. AX753246 and AX753249, respectively; the AAV-9 genome isprovided in Gao et al., J. Virol., 78: 6381-6388 (2004); the AAV-10genome is provided in Mol. Ther., 13(1): 67-76 (2006); and the AAV-11genome is provided in Virology, 330(2): 375-383 (2004).

NAGLU polypeptides contemplated include, but are not limited to, a NAGLUpolypeptide with the amino acid sequence set out in SEQ ID NO: 2.

SGSH polypeptides contemplated include, but are not limited to, a SGSHpolypeptide with the amino acid sequence set out in SEQ ID NO: 4.

The polypeptides contemplated include full-length proteins, precursorsof full length proteins, biologically active subunits or fragments offull length proteins, as well as biologically active analogs (e.g.,derivatives and variants) of any of these forms of polypeptides. Thus,polypeptides include, for example, those that (1) have an amino acidsequence that has greater than about 60%, about 65%, about 70%, about75%, about 80%, about 85%, about 90%, about 91%, about 92%, about 93%,about 94%, about 95%, about 96%, about 97%, about 98% or about 99% orgreater amino acid sequence identity, over a region of at least about25, about 50, about 100, about 200, about 300, about 400, or more aminoacids, to a polypeptide encoded by a nucleic acid or an amino acidsequence described herein.

As used herein “biologically active derivative,” “biologically activefragment,” “biologically active analog” or “biologically active variant”includes any derivative or fragment or analog or variant of a moleculehaving substantially the same functional and/or biological properties ofsaid molecule, such as enzymatic activities.

An “analog,” such as a “variant” or a “derivative,” is a compoundsubstantially similar in structure to and having the same biologicalactivity as, albeit in certain instances to a differing degree, anaturally-occurring molecule.

A “derivative,” for example, is a type of analog and refers to apolypeptide sharing the same or substantially similar structure as areference polypeptide that has been modified, e.g., chemically.

A polypeptide variant, for example, is a type of analog and refers to apolypeptide sharing substantially similar structure and having the samebiological activity as a reference polypeptide (i.e., “nativepolypeptide” or “native therapeutic protein”). Variants differ in thecomposition of their amino acid sequences compared to thenaturally-occurring polypeptide from which the variant is derived, basedon one or more mutations involving (i) deletion of one or more aminoacid residues at one or more termini of the polypeptide and/or one ormore internal regions of the naturally-occurring polypeptide sequence(e.g., fragments), (ii) insertion or addition of one or more amino acidsat one or more termini (typically an “addition” or “fusion”) of thepolypeptide and/or one or more internal regions (typically an“insertion”) of the naturally-occurring polypeptide sequence or (iii)substitution of one or more amino acids for other amino acids in thenaturally-occurring polypeptide sequence.

Variant polypeptides include insertion variants, wherein one or moreamino acid residues are added to a therapeutic protein amino acidsequence of the present disclosure. Insertions may be located at eitheror both termini of the protein, and/or may be positioned within internalregions of the therapeutic protein amino acid sequence. Insertionvariants, with additional residues at either or both termini, includefor example, fusion proteins and proteins including amino acid tags orother amino acid labels.

In deletion variants, one or more amino acid residues in a therapeuticprotein polypeptide as described herein are removed. Deletions can beeffected at one or both termini of the therapeutic protein polypeptide,and/or with removal of one or more residues within the therapeuticprotein amino acid sequence. Deletion variants, therefore, includefragments of a polypeptide sequence.

In substitution variants, one or more amino acid residues of atherapeutic protein polypeptide are removed and replaced withalternative residues. In one aspect, the substitutions are conservativein nature and conservative substitutions of this type are well known inthe art. Alternatively, the present disclosure embraces substitutionsthat are also non-conservative. Exemplary conservative substitutions aredescribed in Lehninger, [Biochemistry, 2nd Edition; Worth Publishers,Inc., New York (1975), pp. 71-77] and are set out immediately below.

Conservative Substitutions

SIDE CHAIN CHARACTERISTIC AMINO ACID Non-polar (hydrophobic): A.Aliphatic A L I V P B. Aromatic F W C. Sulfur-containing M D. BorderlineG Uncharged-polar: A. Hydroxyl S T Y B. Amides N Q C. Sulfhydryl C D.Borderline G Positively charged (basic) K R H Negatively charged(acidic) D E

Alternatively, exemplary conservative substitutions are set outimmediately below.

Conservative Substitutions II

ORIGINAL RESIDUE EXEMPLARY SUBSTITUTION Ala (A) Val, Leu, Ile Arg (R)Lys, Gln, Asn Asn (N) Gln, His, Lys, Arg Asp (D) Glu Cys (C) Ser Gln (Q)Asn Glu (E) Asp His (H) Asn, Gln, Lys, Arg Ile (I) Leu, Val, Met, Ala,Phe, Leu (L) Ile, Val, Met, Ala, Phe Lys (K) Arg, Gln, Asn Met (M) Leu,Phe, Ile Phe (F) Leu, Val, Ile, Ala Pro (P) Gly Ser (S) Thr Thr (T) SerTrp (W) Tyr Tyr (Y) Trp, Phe, Thr, Ser Val (V) Ile, Leu, Met, Phe, Ala

In yet further aspect, the invention provides DNA plasmids comprisingrAAV genomes of the invention. The DNA plasmids are transferred to cellspermissible for infection with a helper virus of AAV (e.g., adenovirus,E1-deleted adenovirus or herpesvirus) for assembly of the rAAV genomeinto infectious viral particles. Techniques to produce rAAV particles,in which an AAV genome to be packaged, rep and cap genes, and helpervirus functions are provided to a cell are standard in the art.Production of rAAV requires that the following components are presentwithin a single cell (denoted herein as a packaging cell): a rAAVgenome, AAV rep and cap genes separate from (i.e., not in) the rAAVgenome, and helper virus functions. The AAV rep and cap genes may befrom any AAV serotype for which recombinant virus can be derived and maybe from a different AAV serotype than the rAAV genome ITRs, including,but not limited to, AAV serotypes AAV-1, AAV-2, AAV-3, AAV-4, AAV-5,AAV-6, AAV-7, AAV-8, AAV-9, AAV-10 and AAV-11. Production of pseudotypedrAAV is disclosed in, for example, WO 01/83692 which is incorporated byreference herein in its entirety.

A method of generating a packaging cell is to create a cell line thatstably expresses all the necessary components for AAV particleproduction. For example, a plasmid (or multiple plasmids) comprising arAAV genome lacking AAV rep and cap genes, AAV rep and cap genesseparate from the rAAV genome, and a selectable marker, such as aneomycin resistance gene, are integrated into the genome of a cell. AAVgenomes have been introduced into bacterial plasmids by procedures suchas GC tailing (Samulski et al., 1982, Proc. Natl. Acad. S6. USA,79:2077-2081), addition of synthetic linkers containing restrictionendonuclease cleavage sites (Laughlin et al., 1983, Gene, 23:65-73) orby direct, blunt-end ligation (Senapathy & Carter, 1984, J. Biol. Chem.,259:4661-4666). The packaging cell line is then infected with a helpervirus such as adenovirus. The advantages of this method are that thecells are selectable and are suitable for large-scale production ofrAAV. Other examples of suitable methods employ adenovirus orbaculovirus rather than plasmids to introduce rAAV genomes and/or repand cap genes into packaging cells.

General principles of rAAV production are reviewed in, for example,Carter, 1992, Current Opinions in Biotechnology, 1533-539; and Muzyczka,1992, Curr. Topics in Microbial. and Immunol., 158:97-129). Variousapproaches are described in Ratschin et al., Mol. Cell. Biol. 4:2072(1984); Hermonat et al., Proc. Natl. Acad. Sci. USA, 81:6466 (1984);Tratschin et al., Mol. Cell. Biol. 5:3251 (1985); McLaughlin et al., J.Virol., 62:1963 (1988); and Lebkowski et al., 1988 Mol. Cell. Biol.,7:349 (1988). Samulski et al. (1989, J. Virol., 63:3822-3828); U.S. Pat.No. 5,173,414; WO 95/13365 and corresponding U.S. Pat. No. 5,658,776; WO95/13392; WO 96/17947; PCT/U598/18600; WO 97/09441 (PCT/US96/14423); WO97/08298 (PCT/US96/13872); WO 97/21825 (PCT/US96/20777); WO 97/06243(PCT/FR96/01064); WO 99/11764; Perrin et al. (1995) Vaccine13:1244-1250; Paul et al. (1993) Human Gene Therapy 4:609-615; Clark etal. (1996) Gene Therapy 3:1124-1132; U.S. Pat. No. 5,786,211; U.S. Pat.No. 5,871,982; and U.S. Pat. No. 6,258,595. The foregoing documents arehereby incorporated by reference in their entirety herein, withparticular emphasis on those sections of the documents relating to rAAVproduction.

The invention thus provides packaging cells that produce infectiousrAAV. In one embodiment packaging cells may be stably transformed cancercells such as HeLa cells, 293 cells and PerC.6 cells (a cognate 293line). In another embodiment, packaging cells are cells that are nottransformed cancer cells such as low passage 293 cells (human fetalkidney cells transformed with E1 of adenovirus), MRC-5 cells (humanfetal fibroblasts), WI-38 cells (human fetal fibroblasts), Vero cells(monkey kidney cells) and FRhL-2 cells (rhesus fetal lung cells).

In another aspect, the invention provides rAAV (i.e., infectiousencapsidated rAAV particles) comprising a rAAV genome of the invention.In some embodiments of the invention, the rAAV genome is aself-complementary genome.

The invention includes, but is not limited to, the exemplified rAAVnamed “rAAV9-CMV-hNAGLU.” The rAAV genome has in sequence an AAV2 ITR,the cytomegalovirus (CMV) immediate early promoter/enhancer, an SV40intron (SD/SA), the NAGLU DNA set out in SEQ ID NO: 1, a polyadenylationsignal sequence from bovine growth hormone and another AAV2 ITR. The DNAsequence of the vector genome is set out in SEQ ID NO: 5. The genomelacks AAV rep and cap DNA, that is, there is no AAV rep or cap DNAbetween the ITRs of the genome.

The invention also includes, but is not limited to, rAAV encoding SGSH.In some embodiments, the rAAV genome has in sequence an AAV2 ITR, theCMV immediate early promoter/enhancer, the SGSH DNA set out in SEQ IDNO: 3, a polyadenylation signal sequence from bovine growth hormone anda AAV2 ITR lacking the terminal resolution site. In some embodiments,the rAAV genome has in sequence an AAV2 ITR, the mouse U1a promoter, theSGSH DNA set out in SEQ ID NO: 3, a polyadenylation signal sequence frombovine growth hormone and a AAV2 ITR lacking the terminal resolutionsite. In some embodiments, rAAV genome has in sequence an AAV2 ITR, themouse U1a promoter, an intron, the SGSH DNA set out in SEQ ID NO: 3, apolyadenylation signal sequence from bovine growth hormone and a AAV2ITR lacking the terminal resolution site. The genomes lack AAV rep andcap DNA, that is, there is no AAV rep or cap DNA between the ITRs of thegenomes.

NAGLU and SGSH DNAs include, without limitation, those that (1)hybridize under stringent hybridization conditions to a nucleic acidencoding an amino acid sequence as described herein, and conservativelymodified variants thereof; (2) have a nucleic acid sequence that hasgreater than about 95%, about 96%, about 97%, about 98%, about 99%, orhigher nucleotide sequence identity, over a region of at least about 25,about 50, about 100, about 150, about 200, about 250, about 500, about1000, or more nucleotides (up to the full length sequence of the matureprotein), to a nucleic acid sequence as described herein. Exemplary“stringent hybridization” conditions include hybridization at 42° C. in50% formamide, 5×SSC, 20 mM Na.PO4, pH 6.8; and washing in 1×SSC at 55°C. for 30 minutes. It is understood that variation in these exemplaryconditions can be made based on the length and GC nucleotide content ofthe sequences to be hybridized. Formulas standard in the art areappropriate for determining appropriate hybridization conditions. SeeSambrook et al., Molecular Cloning: A Laboratory Manual (Second ed.,Cold Spring Harbor Laboratory Press, 1989) §§9.47-9.51.

The rAAV may be purified by methods standard in the art such as bycolumn chromatography or cesium chloride gradients. Methods forpurifying rAAV vectors from helper virus are known in the art andinclude methods disclosed in, for example, Clark et al., Hum. GeneTher., 10(6): 1031-1039 (1999); Schenpp and Clark, Methods Mol. Med.,69: 427-443 (2002); U.S. Pat. No. 6,566,118 and WO 98/09657.

In an additional aspect, the invention contemplates compositionscomprising rAAV of the present invention encoding an NAGLU polypeptide.These compositions may be used to treat mucopolysaccharidosis IIIB. Inother embodiments, compositions of the present invention may include twoor more rAAV encoding different polypeptides of interest.

In still an additional aspect, the invention contemplates compositionscomprising rAAV of the present invention encoding an SGSH polypeptide.These compositions may be used to treat mucopolysaccharidosis IIIA. Inother embodiments, compositions of the present invention may include twoor more rAAV encoding different polypeptides of interest.

Compositions of the invention comprise rAAV in a pharmaceuticallyacceptable carrier. The compositions may also comprise other ingredientssuch as diluents and adjuvants. Acceptable carriers, diluents andadjuvants are nontoxic to recipients and are preferably inert at thedosages and concentrations employed, and include buffers such asphosphate, citrate, or other organic acids; antioxidants such asascorbic acid; low molecular weight polypeptides; proteins, such asserum albumin, gelatin, or immunoglobulins; hydrophilic polymers such aspolyvinylpyrrolidone; amino acids such as glycine, glutamine,asparagine, arginine or lysine; monosaccharides, disaccharides, andother carbohydrates including glucose, mannose, or dextrins; chelatingagents such as EDTA; sugar alcohols such as mannitol or sorbitol;salt-forming counterions such as sodium; and/or nonionic surfactantssuch as Tween, pluronics or polyethylene glycol (PEG).

Titers of rAAV to be administered in methods of the invention will varydepending, for example, on the particular rAAV, the mode ofadministration, the treatment goal, the individual, and the cell type(s)being targeted, and may be determined by methods standard in the art.Titers of rAAV may range from about 1×10⁶, about 1×10⁷, about 1×10⁸,about 1×10⁹, about 1×10¹⁰, about 1×10¹¹, about 1×10¹², about 1×10¹³ toabout 1×10¹⁴ or more DNase resistant particles (DRP) per ml. Dosages mayalso be expressed in units of viral genomes (vg). Dosages may also varybased on the timing of the administration to a human. These dosages ofrAAV may range from about 1×10¹¹ vg/kg, about 1×10¹², about 1×10¹³,about 1×10¹⁴, about 1×10¹⁵, about 1×10¹⁶ or more viral genomes perkilogram body weight in an adult. For a neonate, the dosages of rAAV mayrange from about 1×10¹¹, about 1×10¹², about 3×10¹², about 1×10¹³, about3×10¹³, about 1×10¹⁴, about 3×10¹⁴, about 1×10¹⁵, about 3×10¹⁵, about1×10¹⁶, about 3×10¹⁶ or more viral genomes per kilogram body weight.

Treatment by methods of the invention comprises the step ofadministering an intravenous (IV) effective dose, or effective multipledoses, of a composition comprising a rAAV of the invention to an animal(including a human being) in need thereof. If the dose is administeredprior to development of a disorder/disease, the administration isprophylactic. If the dose is administered after the development of adisorder/disease, the administration is therapeutic. In embodiments ofthe invention, an effective dose is a dose that alleviates (eliminatesor reduces) at least one symptom associated with the disorder/diseasestate being treated, that slows or prevents progression to adisorder/disease state, that slows or prevents progression of adisorder/disease state, that diminishes the extent of disease, thatresults in remission (partial or total) of disease, and/or that prolongssurvival.

Combination therapies are also contemplated by the invention.Combination as used herein includes both simultaneous treatment orsequential treatments. Combinations of methods of the invention withstandard medical treatments (e.g., transient or long-termimmunosuppression) are specifically contemplated, as are combinationswith novel therapies.

Compositions suitable for systemic (IV) use include sterile aqueoussolutions or dispersions and sterile powders for the extemporaneouspreparation of sterile injectable solutions or dispersions. In all casesthe form must be sterile and must be fluid to the extent that easysyringability exists. It must be stable under the conditions ofmanufacture and storage and must be preserved against the contaminatingactions of microorganisms such as bacteria and fungi. The carrier can bea solvent or dispersion medium containing, for example, water, ethanol,polyol (for example, glycerol, propylene glycol, liquid polyethyleneglycol and the like), suitable mixtures thereof, and vegetable oils. Theproper fluidity can be maintained, for example, by the use of a coatingsuch as lecithin, by the maintenance of the required particle size inthe case of a dispersion and by the use of surfactants. The preventionof the action of microorganisms can be brought about by variousantibacterial and antifungal agents, for example, parabens,chlorobutanol, phenol, sorbic acid, thimerosal and the like. In manycases it will be preferable to include isotonic agents, for example,sugars or sodium chloride. Prolonged absorption of the injectablecompositions can be brought about by use of agents delaying absorption,for example, aluminum monostearate and gelatin, and Tween family ofproducts (e.g., Tween 20).

Sterile injectable solutions are prepared by incorporating rAAV in therequired amount in the appropriate solvent with various otheringredients enumerated above, as required, followed by filtersterilization. Generally, dispersions are prepared by incorporating thesterilized active ingredient into a sterile vehicle which contains thebasic dispersion medium and the required other ingredients from thoseenumerated above. In the case of sterile powders for the preparation ofsterile injectable solutions, the preferred methods of preparation arevacuum drying and the freeze drying technique that yield a powder of theactive ingredient plus any additional desired ingredient from thepreviously sterile-filtered solution thereof.

Transduction of cells with rAAV of the invention results in sustainedexpression of NAGLU or SGSH polypeptide. Transduction may be carried outwith gene cassettes comprising tissue specific control elements, forexample, promoters that allow expression specifically within neurons orspecifically within astrocytes. Examples include neuron specific enolaseand glial fibrillary acidic protein promoters. Inducible promoters underthe control of an ingested drug may also be developed.

It will be understood by one of ordinary skill in the art that apolynucleotide delivered using the materials and methods of theinvention can be placed under regulatory control using systems known inthe art. By way of non-limiting example, it is understood that systemssuch as the tetracycline (TET on/off) system [see, for example, Urlingeret al., Proc. Natl. Acad. Sci. USA 97(14):7963-7968 (2000) for recentimprovements to the TET system] and Ecdysone receptor regulatable system[Palli et al., Eur J. Biochem 270: 1308-1315 (2003] may be utilized toprovide inducible polynucleotide expression.

Thus, the invention provides methods of systemically administering aneffective dose (or doses, administered essentially simultaneously ordoses given at intervals) of rAAV of the invention to a patient in needthereof.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a map of the rAAV-CMV-hNAGLU vector genome.

FIG. 2 shows improved behavior and extended survival in MPS IIIB miceafter systemic gene transfer by rAAV-CMV-hNAGLU. FIG. 2 a. Hidden taskin water maze (n⁼11/group). Day 1: test trial. FIG. 2 b. Latency to fallfrom a rotarod (n⁼11/group). FIG. 2 c. Survival (i 5/group, P<0.001).+/+: wt; −/−: MPS IIIB; AAV9-L, AAV9-H: MPS IIIB mice treated with5×10¹² or 1.5×10¹³ vg/kg rAAV9-hNAGLU vector, respectively. *: P<0.05(vs. +/+); #: P<0.05 (vs. AAV9-L); ̂: P<0.05 (vs. AAV9-H); &: P>0.05(vs. −/−). Repeated measures ANOVA analyses: @: day effect P<0.01; $:group (treatment effect) P<0.01; %: day-group interaction P41.020(rotarod).

FIG. 3 shows rAAV9-mediated expression of functional rNAGLU in tissues.Tissues from MPS IIIB mice treated with rAAV9-hNAGLU were assayed forNAGLU activity (6 and 9 mo pi)(n=5-6/group). FIG. 3 a. Dose-response.+/+: wt; AAV9-11, AAV9-L: MPS IIIB mice treated with 1.5×10¹³(AAV9-H) or5×10¹² vg/kg (AAV9-L) vector; FIG. 3 b. Impact of mannitol pretreatment.M+/M−: MPS IIIB mice treated with 2×10¹³ vg/kg vector with (M+) orwithout (M−) mannitol pretreatment. FIG. 3 c. Plasma NAGLU activity(n=3-4). +/−: heterozygotes. No significant difference in tissue NAGLUactivity was detected at 6 and 9 months pi. Data shown are means±SD ofcombined data on tissues from mice at 6 and 9 mo pi. *: P<0.01 vs. +/+;#: P<0.05 vs. AAV9-H or M+: P>0.05 vs. +/+. @: P<0.05 vs. +/−.

FIG. 4 shows the significant reduction of GAG content in the CNS andsomatic tissues. Tissues from MPS IIIB mice treated with rAAV9-hNAGLUwere assayed to quantify GAG content (6 and 9 mo pi). FIG. 4 a. Doseresponse. FIG. 4 b. Impact of mannitol pretreatment. +/Ai wt; −/−: MPSIIIB; AAV9-H, AAV9-L: MPS MB mice treated with 1.5×10¹³ vg or 5×10¹²vg/kg vector; M+, M−: MPS IIIB mice treated with rAAV9 vector (2×10¹³vg/kg) with or without mannitol pretreatment. Data shown are means±SD(n=5-6), combining data from tissues collected at 6 and 9 mo pi. *:P<0.01 vs. +/+; #: P<0.05 vs. AAV9-H or M+; ̂: P<0.05 vs. AAV9-L or M−;+: P>0.05 vs. +/+.

FIG. 5 shows rAAV9-mediated correction of astrocytosis andneurodegeneration in MPS IIIB mice. Brain sections of MPS IIIB micetreated with rAAV9-CMV-hNAGLU vector (6 mo pi) were assayed for GFAP byimmunofluorescence and stained with toluidine blue for histopathology.FIG. 5 a. Number of astrocytes: Data are means±SD of GFAP+ cells per330×433 pm on 6-8 IF-GFAP-staining sections/mouse, from 3 mice/group.FIG. 5 b. Number of purkinje cells: Data are means±SD of purkinjecells/200 p.m (in length) in ansiform lobules in cerebellum on 6toluidine blue stained sections/mouse, from 3 mice/group. NT:non-treated MPS IIIB mouse; AAV9: MPS IIIB mouse treated with rAAV9.CTX: cerebral cortex; ST: Striatum; TH: thalamus; BS: Brain stem. *:P<0.01 vs. non-treated.

FIGS. 6 a and 6 b show rAAV9-mediated expression of functional rSGSH intissues of treated MPSIIIA mice. For each tissue, AAV9, rh74 anduntreated result bars are respectively shown from left to right.

FIG. 7 shows a significant reduction of GAG content in tissues oftreated MPSIIIA mice. For each tissue, AAV9, rh74 and untreated resultbars are respectively shown from left to right.

FIG. 8 shows an improvement in cognitive behavior assays after treatmentof one-month old MPSIIIA mice with low dose scAAV9 or rh74-U1a-SGSH. Inthe lower graphs, for each tissue, untreated, wild type and either AAV9or rh74 result bars are respectively shown from left to right.

FIG. 9 shows a significant reduction of GAG content in tissues ofMPSIIIA mice treated at 2 or 6 months of age. For each tissue, wildtype, untreated, two-month and six-month result bars are respectivelyshown from left to right.

FIG. 10 shows an improvement in cognitive behavior assays aftertreatment of two- or six-month old MPSIIIA mice with high dose scAAV9 orrh74-U1a-SGSH. In the lower graphs, for each tissue, untreated, wildtype and either AAV9 or rh74 result bars are respectively shown fromleft to right.

DETAILED DESCRIPTION

The present invention is illustrated by the following examples relatingto delivery of human NAGLU (hNAGLU) genes to the spinal cord viaintravenous delivery of rAAV9. Example 1 describes rAAV encoding hNAGLU.Example 2 describes the administration of the rAAV encoding hNAGLU toMPSIIIB mice. Examples 3 through 6 describe the beneficial results ofadministration of the rAAV. Example 7 discusses the significance of theresults. Example 8 describes rAAV encoding SGSH. Examples 9 through 11describe administration of various dosages of rAAV encoding SGSH toMPSIIIA mice of varying ages, as well as the beneficial effects of theadministration.

Example 1 Recombinant AAV (rAAV) Viral Vectors Encoding NAGLU

A rAAV vector plasmid, containing AAV2 ITRs, an immediate early CMVpromoter/enhancer, an SV40 intron, a human α-N-acetylglucosaminidasecoding region, a bGH polyadenylation signal sequence, and ampicillinresistance gene, was used to produce a rAAV9-CMV-hNAGLU viral vector.

Recombinant AAV9 viral vectors with the hNAGLU-encoding genome wereproduced in 293 cells using three-plasmid co-transfection, and purifiedas described in Zolotukhin et al., Gene Ther., 6: 973-985 (1999). Thisvector is referred to as “rAAV9-CMV-hNAGLU” herein. The vector genomescontained minimal elements required for transgene expression, includingAAV2 terminal repeats, a human cytomegalovirus (CMV) immediate-earlypromoter, SV40 splice donor/acceptor signal, a human NAGLU codingsequence (SEQ ID NO: 1), and bGH polyadenylation signal. SEQ ID NO: 5 isthe DNA sequence of the vector genome. FIG. 1 is a map of the vectorgenome wherein the length of the various elements of the genome isindicated below the element.

A control self-complementary AAV encoding green fluorescent protein,scAAV9-CMV-GFP was also produced, containing AAV2 terminal repeats, ahuman cytomegalovirus (CMV) immediate-early promoter, SV40 splicedonor/acceptor signal, a eGFP coding sequence, and SV40 polyadenylationsignal.

Example 2 Administration of Viral Vectors

An MPS IIB3 knock-out mouse colony [Li et al., Proc. Natl. Acad. Sci.USA, 96: 14505-14510 (1999) was maintained on an inbred background(C57BL/6) of backcrosses of heterozygotes. All care and procedures werein accordance with the Guide for the Care and Use of Laboratory Animals[DHHS Publication No. (NIH) 85-23]. The genotypes of progeny mice wereidentified by PCR.

To assess the therapeutic efficacy of rAAV9 gene delivery, 4-6-week-oldMPS IIIB mice were treated with an IV injection of rAAV9-CMV-hNAGLU(5×10¹² or 1.5×10¹³ vg/kg, n=11/group). Separately, other MPS IIIB micewere treated with 2×10¹³ vg/kg rAAV9-CMV-hNAGLU, with or withoutmannitol pretreatment (n=5/group), to assess the impact on CNS entry.Controls were sham-treated (phosphate-buffered saline) wild type (wt)and MPS IIIB littermates (n=11). Tissue analyses were carried out at 6months and 9 months (n=2-4/group) post-injection (pi).

Additionally, self-complementary AAV (scAAV) vector carrying acytomegalovirus-green fluorescent protein (CMV-GFP) transgene (5×10¹²vg/kg) was injected IV into 6-8-week-old wt mice (n=4/group) todetermine the distribution of transgene expression (1 month pi), as acomparison to rAAV9-hNaGlu treatment.

Results are presented below.

Example 3 Behavioral Tests

The rAAV9-CMV-hNaGlu-treated MPS BIB mice and controls were tested forbehavioral performance at approximately 5.0-5.5 months of age asfollows.

Hidden Task in the Morris Water Maze

A water maze (diameter=122 cm) was filled with water (45 cm deep, 24-26°C.) containing 1% white TEMPERA paint, located in a room with numerousvisual cues. See Warburton et al., J. Neurosci, 21: 7323-7330 (2001).Mice were tested for their ability to find a hidden escape platform(20×20 cm) 0.5 cm under the water surface. Each animal was given fourtrials per day, across three days, as described previously. Measureswere taken of latency to fmd the platform (sec) via an automatedtracking system (San Diego Instruments). Results are shown in FIG. 2 a.

Rotarod

Mice were tested on an accelerating rotarod (Med Associate, Inc.) toassess motor coordination. See Lijam et al., Cell, 90895-905 (1997).Rotation speed was set at an initial value of 3 revolutions per minute(rpm), with a progressive increase to a maximum of 30 rpm across fiveminutes (the maximum trial length). For the first test session, animalswere given three trials, with 45 seconds between each trial. Twoadditional trials were given 48 hours later. Measures were taken forlatency to fall from the top of the rotating barrel. Results are shownin FIG. 2 b.

Statistical Analyses

Means, standard deviation (SD) and unpaired student t-test were used toanalyze quantitative data. Behavioral measures were taken by an observerblind to experimental treatment. Behavioral testing data were alsoanalyzed using repeated measures ANOVA (SAS 9.1.3) to determine thesignificance of the variances among treatment and control groups andtesting days.

Results of Behavioral Tests

All mice treated IV with 5×10¹² or 1.5×10¹³ vg/kg rAAV9-NAGLU weretested for behavior at 5-5.5 mo of age to assess the neurologicalimpacts. Both dosage groups exhibited significant decreases in latencyto find a hidden platform in a water maze (FIG. 2 a), and significantlylonger latency to fall from an accelerating rotarod (FIG. 2 b), comparedwith non-treated MPS IIIB mice, indicating the correction of cognitiveand motor function. There were no significant differences in behaviorperformance between these two dose groups.

Example 4 Longevity Assessment

Following the rAAV9-hNaGlu vector injection(s), mice were continuouslyobserved for the development of endpoint symptoms, or until deathoccurred. The endpoint was when the symptoms of late stage clinicalmanifestation (urine retention, rectal prolapse, protruding penis) inMPS IIIB mice became irreversible, or when wt control mice were 24months or older. Longevity data were analyzed using Kaplan-Meier method.The significance level was set at P<0.05. Results are shown in FIG. 2 c.

Ten rAAV9-treated MPS IIIB mice, five from each dose group, wereobserved for longevity. All ten survived >16.9 months (with one mouse ofthe low-dose group dying at age of 16.1 months) and the majority of themsurvived 18.9-27.4 months within the normal range of lifespan, while allnon-treated MPS IIIB mice died at 8-12 months of age (P<0.001) (FIG. 2c). These data demonstrate that a single IV rAAV9 vector injection aloneis functionally beneficial in treating the CNS disease and increasinglongevity in MPS IIIB mice.

Example 5 Tissue Analyses

In the therapeutic studies above, tissue analyses were carried out at 6mo and 9 mo post injection (pi). Mice were anesthetized with 2.5%Avertin before tissue collection. Brain, spinal cord and multiplesomatic tissues were collected on dry ice or embedded in OCT compoundand stored at −70° C., before being processed for analyses. Tissues werealso processed for paraffm sectioning.

Tissue samples from scAAV9-GFP vector-treated mice were collected foranalysis 4-5 weeks pi. The mice were anesthetized with 2.5% Avertin andthen perfused transcardially with cold PBS (0.1M, pH7.4), followed by 4%paraformaldehyde in phosphate buffer (0.1M, pH7.4). The entire brain andspinal cord, as well as multiple somatic tissues (including liver,kidney, spleen, heart, lung, intestine and skeletal muscles), werecollected and fixed in 4% paraformaldehyde overnight at 4° C. beforebeing further processed for vibratome sectioning.

NAGLU Activity Assay

Tissues were analyzed at 6 mo and/or 9 mo pi by NAGLU activity assay todetermine the distribution and level of rAAV9-mediated transgeneexpression. Tissue samples were assayed for NaGlu enzyme activityfollowing a published procedure with modification. The assay measures4-methylumbelliferone (4MU), a fluorescent product formed by hydrolysisof the substrate 4-methylumbellireyl-N-acetyla-D-glucosaminide. TheNaGlu activity is expressed as unit/mg protein. 1 unit is equal to 1nmol 4MU released/h at 37° C. Results are shown in FIG. 3.

GAG Content Measurement

GAG was extracted from tissues following published procedures [van deLest et al., Anal. Biochem. 221: 356-361 (1994)] with modification [Fuet al., Gene Ther., 14: 1065-1077 (2007). Dimethylmethylene blue (DMB)assay was used to measure GAG content [de Jong et al., Clin. Chem., 35:1472-1477 (1989)]. The GAG samples (from 0.5-1.0 mg tissue) were mixedwith H₂O to 40 ml before adding 35 nM DMB (Polysciences CEO 03610-1) in0.2 mM sodium formate buffer (SFB, pH 3.5). The product was measuredusing a spectrophotometer (0D535). The GAG content was expressed asμg/mg tissue. Urine GAG content was also measured. Heparan sulfate(Sigma, H9637) was used as standard. Results are shown in FIG. 4.

Immunofluorescence

Immunofluorescence (IF) was performed to identify cells expressinghNAGLU, GFP or glial fibrillary acidic protein (GFAP) for astrocytes,using antibodies against hNaGlu (a kind gift from Dr. EF Neufeld, UCLA),GFP (Invitrogen) or GFAP (Chemicon), and corresponding secondaryantibody conjugated with AlexaFluor⁵⁶⁸ or AlexaFluor⁴⁸⁸ (MolecularProbes). The IF staining was performed on thin cryostat sections (8 p.m)of tissue samples following procedures recommended by the manufacturers.The sections were visualized under a fluorescence microscope.

Histopathology

Tissues were assayed for histopathology to visualize the impact of IVrAAV9-NAGLU gene delivery on the lysosomal storage pathology in MPS IIIBmice. Histopathology was performed following standard methods. Paraffmsections (41.un) were fixed with 4% paraformaldehyde in phosphate buffer(0.1 M, pH 7.2) at 4° C. for 15 min and stained with 1% toluidine blueat 37° C. for 30 min to visualize lysosomal GAG. The sections weremounted, and imaged under a light microscope.

Quantitative Real Time PCR

Total DNA was isolated from tissue samples of treated and nontreated MPSIIIB mice using Qiagen DNeasy columns. Brain DNA was isolated frommidbrain tissue. The DNA samples were analyzed by quantitative real-timePCR, using Absolute Blue QPCR Mix (Thermo Scientific, Waltham, Mass.)and Applied Biosystems 7000 Real-Time PCR System, following theprocedures recommended by the manufacturer. Taqman primers specific forthe CMV promoter were used to detect rAAV vector genomes: f: GGCAGTACATCAAGTGTATC (SEQ ID NO: 6); r: ACCAATGG TAATAG CGATGAC (SEQ ID NO: 7);probe: [6˜FAM]AATGACGGTAAAT GGCCCGC[TAMRA˜6˜FAM] (SEQ ID NO: 8). GenomicDNA was quantified in parallel samples using β-actin specific primers:f: GTCATCAC TATTG GCAACGA (SEQ ID NO: 9); r: CTCAGGAGTTTTGTCACCTT (SEQID NO: 10); probe: [6˜FAM]TTCCGATGCCCT GAGGCTCT[Tamra˜Q] (SEQ ID NO:11). Genomic DNA from nontreated MPS IIIB mouse tissues was used ascontrols or background and absence of contamination. Global CNS andwidespread somatic restoration of NAGLU.

Tissue Analysis Results

Tissues were analyzed at 6 months and/or 9 months pi byimmunofluorescence (IF) and NAGLU activity assay to determine thedistribution and level of rAAV9-mediated transgene expression.NAGLU-specific IF was detected throughout the brains of treated mice, inneurons, glia, and abundant endothelial cells in capillaries and largerblood vessels, in an apparently dose-dependent fashion. No significantdifferences were observed in the distribution or levels of rNaGlu signalbetween 6 months and 9 months pi. NAGLU-positive glial cells were notcontained with anti-glial fibrillary acidic protein (GFAP) Ab, and werelikely to be oligodendrocytes, based on their morphology. Importantly,while rNAGLU IF was observed in the brains of all rAAV9-treated mice,mannitol pretreatment did appear to increase the number of transducedcells in the CNS.

Differential transduction levels were observed in peripheral organs. TherNAGLU protein was detected in 20-40% of hepatocytes, >95% ofcardiomyocytes, and 10-30% of skeletal myocytes. The distribution ofrAAV9-transduced hepatocytes was uniform throughout the liver.Transduction in abundant neurons in myenteric plexus and submucosalplexus of the intestine was observed, suggesting efficient targeting ofthe peripheral nervous system (PNS). The rNAGLU signals were mostlypresent in granules, whereas scAAV9-mediated GFP signals were uniform inthe cytoplasm of transduced cells, suggesting correct lysosomaltrafficking of rNAGLU. Transduction of endothelial cells was alsoobserved in peripheral tissues of rAAV9-GFP vector-treated mice.

Example 6 Enzyme Function Assays

Function of the recombinant NAGLU and resulting effects in animals werealso analyzed in the therapeutic studies above.

rNAGLU Enzymatic Function

Transgene enzymatic activity was assayed to quantify the expression andthe functionality of rAAV9-mediated rNAGLU. There were no significantdifferences in tissue NAGLU activity at 6 and 9 months pi, suggestingstable transduction. The rAAVmediated rNaGlu was metabolicallyfunctional and the tissue rNAGLU activity was dose-dependent, withapproximately normal levels in the brains of mice receiving 5×10¹² vg/kgvector, and supra-physiologic levels in the brains of mice receiving1.5×10¹³ vg/kg (FIG. 3 a). In both dose groups, we detected NAGLUactivity at normal or subnormal levels in the liver, lung and intestine(FIG. 3 a), supra-physiologic levels in the skeletal muscles (FIG. 3 a)and heart (40 & 100 units/mg protein, data not shown), and low levels inthe spleen, but no detectable NAGLU activity in the kidney. A low levelof NAGLU activity was detected in the kidneys of the mice treated with2×10¹³ vg/kg vector (FIG. 3 b). Mannitol pretreatment led to an increasein NAGLU activity in the brain (though not significant due to highindividual variation), liver, spleen, lung and intestine, but a decreasein the heart and skeletal muscle (FIG. 3 b). No detectable NAGLUactivity (<0.03 unit/mg) was observed in tissues from non-treated MPSIIIB mice.

rNaGlu Secretion

Plasma samples were assayed for NAGLU activity to assess the secretionof the enzyme. Activity was detected in the plasma of all rAAV9-treatedMPS MB mice at or near heterozygote levels, though lower than homozygouswt levels (FIG. 3 c). Mannitol pretreatment resulted in significantreduction in plasma NAGLU activity (FIG. 3 c). These data indicate thatthe rNAGLU was secreted, though the source tissue or cell type is notclear.

GAG Content Reduction

Tissues were assayed for GAG content to quantify the impact of IVrAAV9-NAGLU gene delivery on the lysosomal storage pathology in MPS IIIBmice. The single IV rAAV9-NAGLU injection led to a reduction of GAGcontent to normal levels in the brain, liver, heart, lung, intestine andskeletal muscle in mice of all four treatment groups (FIG. 4). Doses of5×10¹² μg or 1.5×10¹³ vg/kg resulted in partial GAG reduction in thespleen but had no impact in kidney (FIG. 4 a).

Treatment with 2×10¹³ vg/kg led to a decrease of GAG to normal levels inthe spleen, and partial GAG reduction in the kidney (FIG. 4 b),consistent with the observed enzyme activity levels.

Histopathology Correction

Histopathology showed complete clearance or reduction of lysosomalstorage lesions in the vast majority of CNS areas, including cerebralcortex, thalamus, brain stem, hippocampus, and spinal cord in all fourtreatment groups. There were decreases in the size, number of vacuoles,and number of cells with lysosomal storage lesions, even in the fewbrain areas that did not show a complete correction, such as purkinjecells and cells in the striatum and hypothalamus. Importantly, themajority of brain and spinal cord parenchymal cells exhibited a welldefined normalized morphology. Immunofluorecence detection for thelysosomal marker, LAMP-1, showed that IV infusion of rAAV9-NAGLU vectorat all doses also resulted in marked reduction of LAMP-1 signal,especially in neurons, throughout the brain. This further supports theconclusion that the amount of vector crossing the BBB was sufficient forefficient correction of CNS lysosomal storage pathology.

In somatic tissues, complete clearance of lysosomal storage lesions inthe livers of all rAAV9-hNaGlu treated mice was observed as well asattenuation of nuclear shrinkage, a marker of cell stress and damage.

Correction of Gliosis and Neurodegeneration

In order to determine whether the rAAV9-hNaGlu vector delivery had animpact on astrocytosis, a major secondary neuropathology of MPS IIIB,brain sections were assayed by immunofluorecence for GFAP expressingcells. Significant decreases in astrocyte numbers in gray matterthroughout the brain of treated mice were observed compared to untreatedat 6 mo and 9 mo pi (FIG. 5 a). Histopathology also revealed significantincreases in the numbers of neurons, such as Purkinje cells (FIG. 5 b),in the brains of treated MPS IIIB mice. These data strongly indicate theamelioration of astrocytosis and neurodegeneration, which are hallmarksof secondary neuropathologies in MPS IIIB, in response to the rAAV9treatment.

Vector Genome Distribution

Quantitative real-time PCR was performed to compare the amount ofrAAV9-CMV-hNaglu vector entering the CNS versus somatic tissues. Table 1shows the distribution of the vector genome in different tissues/organsof MPS IIIB mice treated with IV vector injection at varying doses. Thehighest concentrations of vector genome were detected in liver(8.20±4.73-32.09±3.93 copies/cell), followed by heart (0.07-0.22copies/cell), and brain (0.06±0.001-0.15±0.02 copies/cell), and very lowcopy numbers were detected in other tissues/organs (Table 1). Thisdifferential vector distribution in rAAV9-treated MPS IIIB mice largelycorrelated with the distribution of rNAGLU IF and enzymatic activity.Notably, mannitol pretreatment increased the vector copy numbers in thebrain, correlating with brain NAGLU activity levels. Furthermore, thesedata reflect persistence of vector genome distribution in treated miceat 6 months pi, supporting a stable long-term transduction. Levels ofvector genome copies correlating with rNAGLU activity and distributionwere not detectable, possibly due to difficulties in quantitativeisolation of DNA from muscle tissue.

TABLE 1 Estimated vector genome in the liver and brain of rAAV9- treatedmice Vector genome (copy/cell) Mice n Liver Brain Heart rAAV9-L 2  8.20± 4.73 0.07 ± 0.07 0.07* rAAV9-H 3 10.86 ± 2.94 0.09-10.47 0.13 ± 0.07rAAV9-M− 2 21.97 ± 6.43  0.06 ± 0.001 0.22* rAAV9-M+ 3 32.09 ± 3.93 0.15± 0.02 0.14* Non-treated 1 0.000 0.000 0.00 Mouse tissue samples (6 mopi) were assayed in duplicates for vector genome copy numbers by qPCR.Data is expressed as vector copy/cell (means ± SD). rAAV9-L: IV infusionof 5 × 10¹² vg/kg; rAAV9-H: IV infusion of 1.5 × 10¹³ vg/kg; rAAV9-M−:IV infusion of 2 × 10¹³ vg/kg without mannitol pretreatment; rAAV9-M+:IV infusion of 2 × 10¹³ vg/kg following mannitol pretreatment. *Datafrom 1 sample in duplicates.

Example 7 Discussion

This study demonstrates the first significant therapeutic benefit fortreating MPS IIIB in adult animals from systemic gene delivery to theCNS without additional treatment to disrupt the BBB. A single IVinjection of hNAGLU-expressing rAAV9 vector was sufficient tosignificantly improve cognitive and motor functions, and greatly prolongsurvival in MPS IIIB mice. In the present study using rAAV9, theincreased longevity exceeds the outcome of previous studies using rAAV2vector delivered through either intracisternal injection, or systemicinjection following mannitol pretreatment. The rNAGLU enzyme was clearlysecreted and functional, leading to a significant bystander effect, andefficient degradation of heparan sulfate GAG in CNS tissues.Importantly, the clinically meaningful therapeutic benefits of theIV-delivered rAAV9 vector in MPS IIIB mice were achieved at a lower dosethan the mannitol-facilitated, systemically delivered rAAV2 vector. Theenhanced rAAV9-CNS transduction in response to mannitol pretreatmentsuggests further potential for reducing the vector dose, and theattendant risk and burden to patients.

The IV vector injection resulted in a ubiquitously diffuse, globalrAAV9-NaGlu transduction throughout the CNS, reflecting the expecteddistribution pattern for vascular delivery. This contrasts sharply withthe focal gradient distribution typically achieved through direct brainparenchymal injection, or the periventricular transduction pattern fromintracisternal and intraventricular injection. While similar to thepattern of transgene expression from IV-delivered rAAV2 after mannitolpretreatment, the extent of rAAV9 transduction was significantly higherin all areas of the brain. This correlates with the increased effects onlongevity and cognitive function compared to that previously achievedusing rAAV2-mannitol treatment, and the normal or above normal levels ofNAGLU activity in the CNS. These findings strongly support the use ofthe trans-BBB neurotropic rAAV9 as a vector for CNS gene therapy andreinforce the view that efficient CNS delivery is the most criticalissue for developing therapies to treat MPS IIIB.

The rAAV9-transduced CNS cells include neurons, glia and endothelia.Neuronal cell transduction appears to be non-preferential, includingmost types of neurons throughout the brain. In contrast, thetransduction of glial cells appears to be cell-type specific, targetingpredominantly oligodendrocyte-like cells, though it is unclear whetherthis is a receptor- or promoter-specific phenomenon. In a previousreport [Faust et al., supra] describing predominant transduction ofastocytes after systemic injection of rAAV9 vector in adult mice, ahybrid chicken J3-actin/CMV-enhancer promoter was used, rather than theCMV enhancer-promoter used in the present study.

In normal cells, 5-20% of newly synthesized lysosomal protein issecreted and available to be taken up by neighboring cells, leading tothe by-stander effect. The widespread clearance/reduction of lysosomalstorage pathology, and normalized tissue GAG content, strongly supportan efficient by-stander effect from the rAAV9-mediated rNAGLU. Theabundant transduction of endothelial cells in the brain may be animportant contributor to the effectiveness of rAAV9 gene delivery forMPS IIIB because of the close association between CNS cells and brainmicrovascular endothelial cells, which together constitute theneurovascular unit. While the observed high levels of rNAGLU expressionstem from the transduction of a relatively small number of CNS cells, itis sufficient to correct the neuropathology leading to functionalcorrection of the neurological disorders.

The rAAV9 treatment also led to a regular morphology in CNS cells, andthe correction of major secondary neuropathology, astrocytosis, andneurodegeneration. It is worth noting that this level of correction ofCNS pathology was not achieved in previous studies using rAAV2-hNAGLUvector with mannitol. While neuropathology is the primary cause ofmortality in MPS IIIB patients, somatic correction may provideadditional therapeutic benefits, since lysosomal storage pathologyinevitably manifests in virtually all organs. The IV-delivered rAAV9exhibited broad tropism in peripheral tissues in a distinct pattern, aspreviously reported, reflecting extensive extravasation and cell-typespecific transduction. This led to complete, longterm correction oflysosomal storage in multiple somatic tissues even at a relatively lowdose. Again, relatively low levels of transduction in some tissues wereassociated with clearance of lysosomal storage of GAGs in the organs,consistent with a significant contribution from the by-stander effect ofsecreted rNAGLU enzyme. It is not clear whether the by-standercorrection in peripheral tissues is mediated by enzyme secreted fromneighboring cells within the same tissue, or circulating rNAGLU secretedby more extensively transduced tissues, in a manner analogous to enzymereplacement therapy. However, the observation of partial GAG reductionin the kidney only at the highest vector dose, correlating withdetectable transduction in the kidney only at that dose, suggests thatthe by-stander effect may be primarily local in this tissue. The primarysource of circulating NAGLU may be liver, muscle, or endothelium.However, the decrease in plasma levels in response to mannitolpretreatment correlated with decreased transduction in muscle ratherthan liver, suggesting that liver may not be the primary source.

Another important observation is the efficient transduction of neuronsin myenteric plexus and submucosal plexus of the intestine, potentiallyenabling correction of not only the CNS but also the PNS at all levelsvia systemic delivery. This suggests that neurotropism is a generalproperty of the AAV9 serotype, and not dependent on the specificstructure of the brain neurovascular unit. Broad neurotropism is avaluable property in gene therapy for the treatment of MPS IIIB,considering that lysosomal storage pathology manifests not only in theCNS but also in the PNS.

Example 8 Recombinant AAV (rAAV) Viral Vectors Encoding SGSH

A rAAV vector plasmid was used to produce three differentrAAV9-CMV-hSGSH viral vectors.

The three self-complementary AAV hSGSH vector-producing plasmids wereconstructed using conventional plasmid cloning techniques. Each vectorgenome contains an SGSH coding region (SEQ ID NO: 3) and either themouse U1a promoter, with or without an intron, or a CMV promoter withoutan intron, Each vector genome also contains a bGH polyadenylationsignal. Each self-complementary vector plasmid construct contains oneintact AA2 terminal repeat and one modified AAV2 terminal repeat missingthe terminal resolution site, thereby forcing the replication of dimericself-complementary DNA genomes. Self-complementary AAV hSGSH viralvectors were produced and packaged in AAV serotype 9 capsids. The viralvectors were tested for expression of hSGSH protein and reduction of GAGstorage in human MPS IIIA fibroblasts.

Self-complementary AAV hSGSH viral vectors were tested in an MPS IIIAmouse model having a missense mutation in the SGSH gene [Bhaumik et al.,Glycobiology, 9(12):1389-1396 (1999)] as described in the examplesbelow.

Example 9

MPS IIIA mice were injected at 10 weeks of age with 5×10¹² vgp/kg) ofscAAV-U1a-hSGSH vector encapsidated in either AAV9 or AAVrh74 serotype.At 10 days post-injection, the mice were euthanized and assays wereperformed to determine the effects of the treatment.

hSGSH transgene expression was assayed. Tissues analyzed included kidney(Kid), heart (Hrt), intestine (Int), skeletal muscle (Mus), lung, brain,Liver (Liv), spleen (Spl) and serum. FIG. 6 shows enzyme expressionrelative to untreated MPS IIIA mice at the same age (−/−). ThescAAV-SGSH vectors reached the CNS and expressed the transgene withindays of administration. FIG. 7 shows GAG content measured in the kidney(Kid), heart (Hrt), muscle (Mus), lung, brain, Liver (Liv) and spleen(Spl).

Sections of CNS and somatic tissues were stained with the lysosomalmarker, Lamp1, revealing clearance of lysosomal storage pathology.Histopathology additionally revealed numerous clear vacuoles present inuntreated mice but corrected in treated animals.

Example 10

The therapeutic effects of scAAV-SGSH treatment at a low vector dosewere examined.

Vector was administered by tail vein injection in MPS IIIA mice at onemonth of age at an approximately 25-fold lower dose than in Example 9.MPS IIIA mice were treated with 1.7×10¹¹ vgp/kg scAAV9-U1a-hSGSH or2.7×10¹¹ vgp/kg scAAVrh74-U1a-hSGSH vector.

At three months post-injection, expression of SGSH in the CNS wasobserved by immunofluroescence staining. Correction of astrocytocis, ahallmark of neuroinflamation associated with MPS IIIA pathology, wasalso observed.

At 7-7.5 months age, the animals were tested for learning ability in theMorris water maze. As shown in FIG. 8, compared to untreated controls,treated animals were similar to wt mice in their latency to locate thehidden platform (upper charts) and spent more time in the zone (4) wherethe platform had been in the previous tests when the platform wasremoved (lower charts).

Example 11

Therapeutic effects of scAAV treatment at high dose at late stage ofdisease were also examined.

MPS IIIA mice were treated with a high dose (5×10¹² vgp/kg) ofscAAV9-U1a-hSGSH vector at 6 months of age, after significantneuropathology had already developed. At 7-7.5 months age, the animalswere tested for learning ability in the Morris water maze. At 7.5 monthsof age, the mice were euthanized and tissues assayed forglycosaminoglycan (GAG) content. Tissues analyzed include liver (Liv),kidney (Kid), heart (Hrt), brain, spleen (Spl), lung, skeletal muscle,and intestine.

FIG. 9 shows clearance of accumulated GAGs in different tissues,including CNS. FIG. 10 shows, compared to untreated controls, treatedanimals were similar to wt mice in their latency to locate the hiddenplatform (upper charts) and spent more time in the zone (4) where theplatform had been in the previous tests when the platform was removed(lower charts).

While the present invention has been described in terms of variousembodiments and examples, it is understood that variations andimprovements will occur to those skilled in the art. Therefore, onlysuch limitations as appear in the claims should be placed on theinvention.

All documents referred to in this application are hereby incorporated byreference in their entirety.

1-17. (canceled)
 18. A method of delivering an N-sulphoglucosaminesulphohydrolase polynucleotide to the central nervous system comprisingthe step of systemically administering a rAAV9 or rh74 comprising aself-complementary genome including the polynucleotide to a patient.19-26. (canceled)
 27. A method of treating mucopolysaccharidosis IIIAcomprising the step of systemically administering a rAAV9 or rh74comprising a self-complementary genome including an N-sulphoglucosaminesulphohydrolase polynucleotide to a patient. 28-31. (canceled)
 32. Themethod of claim 18 wherein mannitol is administered prior to theadministration of the rAAV.
 33. The method of claim 27 wherein mannitolis administered prior to the administration of the rAAV.
 34. The methodof claim 18 wherein the sequence of the N-sulphoglucosaminesulphohydrolase polynucleotide is set out in SEQ ID NO:
 3. 35. Themethod of claim 27 wherein the sequence of the N-sulphoglucosaminesulphohydrolase polynucleotide is set out in SEQ ID NO:
 3. 36. Themethod of claim 32 wherein the sequence of the N-sulphoglucosaminesulphohydrolase polynucleotide is set out in SEQ ID NO:
 3. 37. Themethod of claim 33 wherein the sequence of the N-sulphoglucosaminesulphohydrolase polynucleotide is set out in SEQ ID NO: 3.